Montelukast

FDA informed healthcare professionals and patients of the Agency's investigation of the possible association between the use of Montelukast and behavior/mood changes, suicidality (suicidal thinking and behavior) and suicide. Montelukast is a leukotriene receptor antagonist used to treat asthma and the symptoms of allergic rhinitis, and to prevent exercise-induced asthma. Patients should not stop taking Montelukast before talking to their doctor if they have questions about the new information. Healthcare professionals and caregivers should monitor patients taking Montelukast for suicidality (suicidal thinking and behavior) and changes in behavior and mood.
This early communication is in keeping with FDA’s commitment to inform the public about its ongoing safety reviews of drugs. Due to the complexity of the analyses, FDA anticipates that it may take up to 9 months to complete the ongoing evaluations. As soon as this review is complete, FDA will communicate the conclusions and recommendations to the public.

Source: http://www.fda.gov/cder/drug/early_comm/montelukast.htm